1. Field of the Invention
The present invention relates to an air spoiler for an automotive vehicle, on which proper reinforcement members are molded integrally so as to increase attachment force of the air spoiler onto rear side surface of trunk lid of the automotive vehicle. Also, the present invention relates to a method for manufacturing an air spoiler for an automotive vehicle by air-blowing, where proper reinforcement members are molded integrally when air-blow molding the air spoiler.
2. Discussion of Related Art
As is well known, many kinds of air spoilers designed in harmony with specific exterior of automotive vehicle have been developed and widely used. The primary function of the air spoiler intended is for suppressing the automotive vehicle, being floating due to strong air current formed while running at high speed, toward road surface so as to increase driving stability and braking force of the automotive vehicle.
Referring to FIGS. 1 and 2, a typical air spoiler denoted by reference numeral 10 is disposed across the rear side, that is, trunk lid 14 of a vehicle 12. Conventionally, a plurality of attachment members 16, each having at least one securement screw 16a such as a T-bolt, are provided at the bottom surface of the air spoiler 10. The attachment members 16 serve to space the air spoiler 10 from the upper surface of the trunk lid 14 by a predetermined interval. The respective securement screws 16a for fitting the air spoiler 10 on the trunk lid 14 of the vehicle 12, are buried integrally in the corresponding attachment member 16 in the process of molding the air spoiler 10. Here, according to an exemplary process for manufacturing the prior art air spoiler, raw material, for example, thermoplastic resin from a source tank is passed through a rotary feeding screw via a hopper of the spoiler molding machine. At this time, the raw material is heated to be melted. Then, the melted raw material is passed through a head of the spoiler molding machine to be changed in cylindrical shape and supplied, in turn, between a core mold and a cavity mold which are open at present.
Referring now to FIG. 2, while the core mold is designed to form an upper part of the air spoiler 10, the cavity mold is to form a lower part including the attachment member 16 of the air spoiler 10, centering around a mold mating surface 18.
Consequently, when the cylindrical raw material has been supplied into the core and cavity molds via the head of the spoiler molding machine, the core and cavity molds are tightly closed. Then, an air cylinder of the spoiler molding machine moves forward and a plurality of blow pins of the spoiler molding machine form a plurality of air-blowing holes on the surface of the raw material supplied into the core and cavity molds in order to blow air through the air-blowing holes of the raw material for a predetermined period.
When the air blowing is completed, the air cylinder of the spoiler molding machine moves backward to its original position. Then, the core and cavity molds open slowly and a molded product, that is, a molded product of air spoiler is taken out by means of a product taking-out machine. The molded air spoiler is subjected to remove undesirable refuses, such as burr. Subsequently, an end-product, a desired air spoiler including attachment members formed integrally is obtained.
In such a conventional process for manufacturing the air spoiler, the respective attachment member 16 have the securement screws 16a such as a T-bolt buried integrally at the bottom surface of the air spoiler 10 so as to attach the air spoiler 10 onto the trunk lid 14 of the automotive vehicle 12.
When the raw material of the air spoiler is subjected to an air blowing stage, where the core mold is tightly closed with the cavity mold, in order to manufacture the aforementioned structure of the air spoiler 10, the raw material for molding the air spoiler 10 must be uniformly injected into the area where the attachment members 16 are to be formed on the cavity mold along the depth direction of the attachment members 16. However, in fact, during air-blowing process the raw material for molding the air spoiler 10 is injected irregularly into the attachment members 16 to be formed on the cavity mold. That is, undesirably, the raw material for molding the air spoiler 10 is gradually thinly injected into the area where the attachment members 16 are to be formed on the cavity mold as seen from a symmetric sectional view of FIG. 2.
If the thickness of the attachment members 16 is irregularly molded, durability of the area where the securement screws 16a are buried on the attachment members 16 is disadvantageously deteriorated. Accordingly, when the air spoiler 10 having the weakened area on the attachment member 16 is mounted on the surface of the trunk lid 14 of the automotive vehicle 12, the area of the attachment members 16 where the securement screws 16a are buried may be damaged or destroyed unexpectedly. Further, when the poor quality air spoiler 10 having the weakened attachment members 16 is mounted on the trunk lid 14 of the automotive vehicle 12, the stability of the automotive vehicle 12 is also deteriorated undesirably during running at high speed. Besides, it brings restriction on designing the molding process of the air spoiler 10.